Blind stitch sewing machine



p 12, 1939- L. G. BOWMAN BLIND STITCH SEWING MACHINE 5 Sheets-Sheet 1Filed Dec. 28, 1936 Ema/whom $0018 6?. Bowman Sept. 12, 1939. L g BOWMAN2,172,494

BLIND STITCH SEWING MACHINE F'ild Dec. 28; 1936 5 Sheets-Sheet 2 1:: a-EM p 1939- L. G. BOWMAN BLIND STITCH SEWING'MACHINE 5 Sheets-Sheet 4.Filed Dec. 28, 1936 Sept. 12, 1939. G. BOWMAN BLIND STITCH SEWINGMACHINE Filed Dec. 28, 19:56 I 5 Sheets-Sheet 5 Louis 6:. BowmanPatented Sept. 12, 1939 UNITED STATES PATENT OFFICE v BLIND STITCHSEWING MACHINE Application December 28, 1936, Serial No. 117,940

34 Claims.

This invention relates to new and useful improvements in blind stitchsewing machines generally, although more particularly to blind stitchmachines of the single thread chain stitch type adapted especially forhemining operations.

It is a well known fact that if the last formed needle thread loop inthe stitched seam is not locked, the entire line of stitches may bepulled out accidentally.

Among the several objects of my invention are to provide means forsevering the thread whereby when the seamed article is removed from themachine the last formed needle loop in the seam will be locked by thetrailing end of the thread; to provide such severing means which willalso function to pull off thread from the supply; to provide a clamp forclamping the supply end of the thread adjacent the point of severancewhereby when the machine is again operated the stitch forming mechanismwill immediately function, and to provide means for operating the threadsevering means upon depression of the work support.

With these and other objects in view which will more fully appear, thenature of the invention will be more clearly understood by following thedescription, the appended claims, and the several views illustrated inthe accompanying drawings.

In the drawings Figure 1 is a front elevation of a blind stitch sewingmachine embodying my invention,

Figure 2 is a top plan view thereof,

Figure 3 is an enlarged section showing the thread carrier and theactuating means therefor in their normal positions,

Figure 4 is a similar View but showing the thread carrier and theactuating means therefor in their operative positions,

Figure 5 is an enlarged detail plan View showing the presser foot, theneedle, the looper, the stitched fabric, and the thread carrier,

Figure 6 is a plan View of the completed seam showing the last formedneedle thread loop locked by the trailing end of the thread,

Figures 7, 8 and 9 are views of the thread clamp and stationary knife,and

Figure 10 is a perspective view of the thread carrier.

Like reference numerals designate corresponding parts throughout theseveral figures of the drawings.

My invention is adapted especially for joining a hem A to a body fabricB by a line of blind stitches of the single thread chain stitch type, as

shown in Figure 6. A needle thread 0 is employed to form the stitchesand the needle loops 0 are spaced equidistantly apart, and theconnecting portions of the thread between the loops are arranged in astraight line and in parallelism to the inner edge a of-the hem.

The machine to which my invention is applied is disclosed in Patent2,030,751, issued to Joseph Mann on Feb. 11, 1936, and includes a mainframe comprising a base 5 having a standard 6 projecting from the rearright hand corner thereof, an arm I which extends laterally from theupper end of the standard, and an arm 8 which extends forwardly from theleft hand end of the arm 1. Fixed to the free end of the arm 8 is ahorizontal presser foot 9 having a centrally located and longitudinallyextending opening l0 therein. The foot is attached at its rear end tothe arm by a screw II, and the front portion of the foot is held againstflexing by spaced posts l2, [3 which are connected to the opposite sidesof the foot and to the arm. J ournaled in the arm 1 of the frame is amain shaft I4, the left hand end thereof projecting across the rear endof the arm 8. Journaled in the arm 8 and extending longitudinallythereof is an oscillatory needle shaft l5 which is driven from the mainshaft by the usual connections. The needle shaft I5 is disposed directlyabove the opening H) in the foot, and fixed to the outer end of theshaft is a needle arm l6 carrying a curved needle ll. Thus when theneedle shaft is oscillated the needle will reciprocate transverselyacross and above the opening ID in the presser foot. It will be notedthat the penetrating stroke of the needle, as viewed from the front ofthe machine, is from right to left. Rigid with the base 5 are posts l8which are located in a plane in advance of the standard 6 and a worksupport I9 is pivotally supported as at l9a on the upper ends of theseposts and includes a lateral extension 20 which projects under thepresser foot 9, and an arm I92: which projects rearwardly beyond thepivot [9a, the work support being yieldably held against depression by aspring 2|. An adjustable screw I9c is threaded into the rearwardlyextending arm l9b for engagement with a part of the machine frame forvariably limiting the upward movement of the work support. Areciprocatory ridge forming element R which in the present machine isshown as a disc, is provided for projecting nodes of fabrics upwardlythrough the opening H3 in the foot into needle penetrating position.This disc R is fixed to a rock shaft 22 journaled on the underside ofthe ated in the usual manner from the main shaft M. In order to form theline of single thread chain stitches, I employ a complemental stitchforming mechanism which cooperates with the needle I1 and includes aloop taker 'X. This loop taker is in the form of a non-thread carryinglooper having an arcuate beak 21 and an' at- I taching shank 28, thelatter being secured to a holder 29 by a clamp screw 38. The holder 29is clamped by a screw 3| to the lower end of a vertically disposed rockshaft 32 which is journaled in a bracket 33 attached to the forward endof the frame arm 8 by screws 34, the shaft 32 and the loop taker X beinglocated above the presser foot 9 and at the left of the opening ||ltherein. The shaft 32 is also disposed in front of the vertical planecontaining the path of needle recipv rocations. The beak 21 of the looptaker extends rearwardly relative to the shank 28 and oscillates in ahorizontal plane above the needle l8.

. end of the looper shaft 32 is a rearwardly extending rock arm 35and-pivotally connected to the rear end thereof is one end of a link 31,the other end'of said link beingconnected to the upper end of a rock arm38 fixed t0 the needle shaft i5. Fixed to the presser foot 9 by a screw39 is a thread loop abutment 40 which is located intermediate the looperX and the left hand wall of the opening I0, and the forward end 4| ofthe abutment being located at a point slightly in rear of the verticalplane. containing the path of needle travel.

In operation of the machine as thus far described, the machine is loadedin the usual manner by first depressing the work support l9 andinserting the body fabric A and hem B under the presser foot 9, the bodyfabric extending to the left of the hem, whereby the needle l8 willenter the hem and have its penetrating or forward movement towards theinner edge of the hem. The needle after passing through the hem willthen enter and emerge from the upper face of the body fabric at a pointunder the hem and in spaced relation to the inner edge thereof. As theneedle begins to recede, it casts out the usual needle thread loop andthe beak of the looper will then enter said loop. As soon as the needlepoint is withdrawn from the hem, the fabric will be fed rearwardly astitch length distance, and during this time the looper will completeits rearward or loop taking movement and the needle loop which is aroundthe looper will be fed rearwardly against the forward end 4| of theabutment 49 which functions to maintain the needle loop in open relationand in the proper position to be entered by the needle on its nextforward stroke.

As previously stated, my invention is applied to the above describedblind stitch machine, and functions (1) to cut'the leg 0 of the needlethread C whereby when the work support is depressed and the hemmedfabric is withdrawn from the the next stitching operation, and (3) toclamp the supply thread at the cut end thereof until two or morestitches have been formed in said next stitching operation.

a To this end, I have provided a thread cutting mechanism which includesa stationary knife D iandra cooperating movable thread carrier E whichare located above the presser foot .9. The

knife D isformed. from a thin strip of metal and includes an attachingarm 42 and a blade 43 arranged in planes at right angles to each other,the lower edge of the blade being sharpened as indicated at 44. The arm42 is located immediately in rear of the vertical plane containing thepath of travel of the needle, and is secured to the attaching arm 45 ofa thread clamp F by a screw 46, and the attaching arm '45 is secured tothe front end of the frame arm 8 by screws 41, the blade'43 extendingrearwardly and being located at the right of the presser foot openingl0, and the sharpened edge 44 being located above and in spaced relationto the foot.

The thread clamp or nippers F includes a downwardly extending andrelatively rigid front arm 48 which is preferably integral with theattaching arm 45, and a relatively flexible rear arm 49 disposed in rearof and in parallelism with the front arm 48 and secured at its upper endthereto by a screw 58. The lower end of the front arm is curvedforwardly as at 5| and cooperates with the lower end of the rear arm 49to form a resultant thread receiving throat 52 which is,

located at the right of the presser foot opening l0 and directly abovethe leg 0 of the needle 0 which is around the looper X when the needleis at the rear end of its stroke.

The thread carrier E is mounted on the presser foot and is movableupwardly to engage the leg 0 of the thread and elevate the same into thethread clamp F and then into cutting cooperation with the knife D,whereby (1) thread will be pulled from the supply, (2) the supply end ofthe leg 0 of the thread will be clamped, and (3) the leg 0 will besevered. The thread. carrier E comprises a rock arm 53 which is prefereably constructed integral with a rock shaft 54, and the outer end of thearm is forked to form resultant spaced thread supporting arms 55, 55 andan inwardly extending slot 56 therebetween, the upper faces of the armsadjacent their outer ends being provided with recesses or seats 51, 51,and the slot being disposed in vertical alinement with the blade 43 ofthe stationary knife D. I

A horizontal bearing plate 58 is attached by screws 59 to the upper faceof the presser foot on the right hand side of the opening I0 and in rearof thepath of movement of the needle. The

plate is provided with spaced transverse bearrock shaft 54, and isnormally positioned in a longitudinally extending slot 65 formed in thepresser foot 9 on the right of the slot Ill therein. A coil spring 66has one end connected to an upwardly extending rock arm 61 fixed to therock shaft 54 intermediate the bearings 60, 6! and has its other endfixed to an anchor plate 68 attached to the right hand post 13 of thepresser foot. The spring functions to yieldably retain the threadcarrier arm 53 in its normal position within the slot 65, the downwardmovement of the arm being stopped by the arm contacting the foot at therear end of the slot. Thus, when the rock arm 63 is depressed, thethread carrier arm 53 will be elevated against the tension of the spring56, and the carrier arms 55, 55 will be positioned on opposite sides ofthe blade 43 of the stationary knife D.

It is desirable to actuate the thread carrier E immediately prior to thestitched article being removed from the machine in order to effect alocking of the needle loop of the last formed stitch. To this end, Ihave provided means for actuating the carrier E upon depression of thework support. For this purpose, a vertical arm 6.: is rigidly connectedto the left side of the rearwardly extending arm l9b of the work supportand at a point adjacent the lateral arm I of the main frame. Ahorizontal arm Ill which is fixed to the upper end of the arm 69, isdisposed in parallelism with the lateral arm 1 and terminates at itsfree end in spaced relation to the forwardly extending frame arm 8 at apoint in rear of the rock arm 63. A bearing arm H is attached to theframe arm 8 intermediate the horizontal arm 10 and the rock arm 63, anda lever 12 extends in parallelism with the frame arm 8 and is fulcrumedintermediate its ends as at 13 on said bearing arm H. The forward end ofthe lever 12 carries a laterally extending pin M which overlies the rockarm 63 and the rear end of the lever overlies the free end of thehorizontal arm in. The lower rear edge of the lever is cut away as at 15to permit the arm Hi to continue its forward and upward movement afterthe thread carrier arm 53 has been elevated to its operative positionwith respect to the stationary knife D, without imparting unnecessaryadditional movement to said thread carrier arm, as shown in Figure 4.

In operation, after a hem has been seamed, the machine is stopped withthe needle at the be ginning of its stroke, the work support 59 is then.depressed by a treadle or knee-press which is connected thereto in theusual manner, and the seamed hem is then withdrawn from the machine.During the depression movement of the work support, the horizontal armH! which is mounted on the rear extension 58b thereof, is elevated andraises the rear end of the lever !2 which is fulcrumed on the frame arm8. The downward movement of the front end of the lever swings the rockarm 63 downwardly and this effects the elevation of the thread carrierarm 53 to raise the leg 0 of the needle thread loop which is around thelooper into the throat 52 and then between the clamping or nipping arms5&3, of the thread clamp F. The carrier arm 53 moves upwardly betweenthe looper and the thread clamp F, and after the thread has been nippedby the clamp, it is moved upwardly into cooperative relation with thestationary knife and there severed. It will be observed that a longlength of trailing thread is thus privided where by when the stitchedhem is withdrawn from the machine, the last formed needle loop will belocked and the length of said trailing thread will suffice to preventthe same from being accidenta1- ly withdrawn from said loop. After thethread has been thus severed, the supply end of the thread will remainin the clamp F until after at least two stitches have been formed in thenext stitching operation, the retention of this supply end of the threadby the clamp insuring the formation of stitch during the first forwardtravel of the needle. I

It will be also observed that inasmuch as the thread supply is anchoredby reason of the needle thread loop extending around the looper, theupward movement of the carrier arm 53 will pull off from the supply asufficient amount of thread which will be retained by the thread clampuntil two 01' more stitches have been formed in the next seamingoperation.

It is of course to be understood that the details of structure andarrangement of parts may be variously changed and modified without deandthe needle when the latter is at the beginning of its forward stroke tosever the leg of the needle thread loop extending around the looper.

2. In a single thread blind stitch sewing machine, the combination witha stationary presser foot having an opening therein, of a threadedneedle located above the foot for reciprocatory movements across theopening thereof, a nonthread-ed looper located above the foot for cooperation with said needle, a ridge forming element for projecting aridge of fabric upwardly through the opening into needle penetratingposition, a stationary knife located above the foot and between thelooper and the needle when the latter is at the beginning of its stroke,and a manually operable carrier for raising the leg of the needle loopext-ending around the looper into cooperative cutting relation with saidknife.

3. In a single thread blind stitch sewing machine, the combination witha stationary presser foot having an opening therein, of a threadedneedle located above the foot for reciprocatory movements across theopening thereof. a nonthreaded looper located above the foot forcooperation with said needle. a ridge forming element for projecting aridge of fabric upwardly through the opening into needle penetratingposition, a stationary knife located above the foot and between thelooper and the needle when the latter is at the beginning of its stroke,and a manually operable carrier for raising the leg of the needle loopextending around the looper into cooperative cutting relation with saidknife, said carrier comprising an arm fulcrumed on the presser foot inrear of the needle path and having its forward end normally disposedunder said leg of said needle loop, the free end of the arm beingslotted to form resultant thread sup- 75 knife.

4. In a single thread blind stitch sewing machine, the combination witha stationary presser foot having an opening therein, of a threadedneedle located above the foot for recip-rocatory movements across theopening thereof, a nonthreaded looper located above the foot for cooperation with said needle, a ridge forming element for projecting aridge of fabric upwardly through the opening into needle penetratingposition, a stationary knife located above the foot and between thelooper. and the needle when the latter is at the beginning of itsstroke, and a manually operable carrier for raising the leg of theneedle loop extending around the looper into cooperative cuttingrelation with said knife, said carrier comprising an arm fulcrume-d onthe presser foot in rear of the needle path and having its forward endnormally disposed under said leg of said needle loop, the free end ofthe arm being slotted to form resultant thread supporting arms movableto opposite sides of the knife,

the upper faces of the arms being recessed to form thread seats. 7

5. In a single thread blind stitch sewing machine, the combination witha stationary presser foot having an opening therein, of a threadedneedle located above the foot for reciprocatory movements across theopening thereof, a nonthreaded looper located above the foot forcooperation with said needle, a ridge forming element for projecting aridge of fabric upwardly through the opening into needle penetratingposition, a stationary'knife located above the foot and between thelooper and the needle when the latter is at the beginning of its stroke,and a manually operable carrier for raising the leg of the needle loopextending around the looper into cooperative cutting relation with saidknife, said carrier comprising an arm fulcrumed on the presser foot inrear of the needle path and having its forward end normally disposedunder said leg of said needle loop, means for yieldably retaining thecarrier arm against upward move ment, and manually operable means forraising the carrier arm against the tension of said yieldable means.

6. In a single thread blind stitch sewing machine, the combination witha stationary presser foot having an opening therein, of a threadedneedle located above the foot for reciprocatory movements across theopening thereof, a nonthreaded looper located above the foot forcooperation with said needle, a ridge forming element for projecting aridge of fabric upwardly through the opening'into needle penetratingposition, a thread clamp located between the looper and the needle whenthe latter is at the beginning of its forward stroke,,a thread cuttingknife, and means located between the thread clamp and the looper forfirst positioning the leg of the needle loop extending around the looperinto the thread clamp and for subsequently moving said threadintosevering relation with said knife.

'7. In a single thread blind stitch sewing machine, the combination witha stationary presser foot having an opening therein, of a threadedneedle located above the foot for reciprocatory movements across theopeningthereof, a nonthreaded looper located above the foot forcooperation with said needle, a ridge forming element for projecting aridge of fabric upwardly through the opening into needle penetratingposition, a

thread clamp located between the looper and the needle when the latteris at the beginning of its forward stroke, a thread cutting knife andmeans located between the thread clamp and the looper for firstpositioning the leg of the needle loop extending around the looper intothe thread clamp and for subsequently moving said thread into severingrelation with said knife, said clampv chine, the combination with astationary presser foot having an opening therein, of a threadedneedle'located above the foot for reciprocatory movements across theopening thereof, a non threaded looper located above the foot forcooperation with said needle, a ridge forming element for projecting aridge of fabric upwardly through the opening into needle penetratingposition, a thread clamp located between the looper and the needle whenthe latter is at the beginning of its forward stroke, a thread cuttingknife, andlmeans located between the thread clamp and the looper forfirst positioning the leg of the needle loop extending around the looperinto the thread clamp and for subsequently moving said thread intosevering relation with said knife, said positioning means comprising acarrier arm fulcrumed on the presser foot in rear of the needle path andhaving its forward end normally disposed under said leg of the needleloop.

9. In a single thread blind stitch sewing machine, the combination witha stationary presser foot having an opening therein, of a threadedneedle located above the foot for reciprocatory movements across theopening thereof, a nonthreaded looper located above the foot forcooperation with said needle, a ridge forming element for projecting aridge of fabric upwardly through the opening into needle penetratingposition, a thread clamp located between the looperand the needle whenthe latter is at the beginning of its forward stroke, a thread cuttingknife, and means located between the thread clamp and the looper forfirst positioning the leg of the needle loop extending around the looperinto the thread clamp and for subsequently moving said thread intosevering relation wth said knife, said positioning means comprising acarrier arm fulcrumed on the presser foot in rear of the needle path andhaving its forward end normally disposed under said leg of the needleloop, means foryieldably retaining thecarrier arm against upwardmovement, and manually operable means for raising the carrier armagainst the tension of said yieldable means.

10. In a single thread blind stitch sewing machine, the combination witha stationary presser foot having an opening therein, of a threadedneedle located above the foot for reciprocatory movements across theopening thereof, a nonthreaded looper located above the foot forcooperation with said needle, a ridge forming element for projecting aridge of fabric upwardly through the opening into needle penetratingposition, a thread clamp located between the looper and the needle whenthe latter is at the beginning of its clamp and the looper for firstpositioning the leg of the needle loop extending around the looper intothe thread clamp and for subsequently cooperating with the knife insevering said thread,

said last named means including a carrier arm fulcrumed on the presserfoot in rear of the needle path and having its forward end normallydisposed under said leg of the needle loop, the free end of the armbeing slotted to form resultant thread supporting arms movable toopposite sides of the knife, means for yieldably retaining the carrierarm against upward movement, and manually operable means for raising thecarrier arm against the tension of said yieldable means.

11. In a single thread blind stitch sewing machine, the combination witha stationary presser foot having an opening therein, of a threadedneedle located above the foot for reciprocatory movements across theopening thereof, a nonthreaded looper located above the foot forcooperation with said needle, a ridge forming element for projecting aridge of fabric upwardly through the opening into needle penetratingposition, a thread clamp located between the looper and the needle whenthe latter is at the beginning of its forward stroke comprisingvertically disposed clamping arms forming a resultant thread receivingthroat at their lower end and located directly above said leg of theneedle loop, a thread cutting knife, and means located between thethread clamp and the looper for first positioning the leg of the needleloop extending around the looper into the thread clamp and forsubsequently moving said thread into severing relation with said knife,said positioning means comprising a carrier arm fulcrumed on the presserfoot in rear of the needle path and having its forward end normallydisposed under said leg of the needle loop.

12. In a single thread blind stitch sewing machine, the combination witha stationary presser foot having an opening, a threaded needle locatedabove the foot for reciprocations transversely across the presser footopening, a ridge forming element for projecting a ridge of fabricupwardly through the opening into needlepenetrating position, means forfeeding the fabric to the needle, a non-threaded looper located abovethe foot and operating entirely on the side of the ridge forming elementopposite the point of needle penetration in the fabric for engaging theneedle thread loop and holding the same for re-entrance by the needle,and thread severing means operative above the foot and between thelooper and the needle when the latter is at the beginning of its stroke.

13. In a single thread blind stitch sewing machine, the combination witha stationary presser foot having an opening, a threaded needle locatedabove the foot for reciprocations transversely across the presser footopening, a ridge forming element for projecting a ridge of fabricupwardly through the opening into needle penetrating position, means forfeeding the fabric to the needle, a non-threaded looper located abovethe foot and operating entirely on the side of the ridge forming elementopposite the point of needle penetration in the fabric for engaging theneedle thread loop and holding the same for re-entrance by the needle, astationary knife located above the foot and between the looper and theneedle when the latter is at the beginning of its stroke, and a manuallyoperable carrier arm for raising the leg of the needle loo-p extendingaround the looper into cooperative cutting relation with said knife.

14. In a single thread blind stitch sewing machine, the combination witha stationary presser foot having an opening, a threaded needle locatedabove the foot for reciprocations transversely across the presser footopening, a ridge forming element for projecting a ridge of fabricupwardly through the opening into needle penetrating position, means forfeeding the fabric to the needle, a non-threaded looper located abovethe foot and operating entirely on the side of the ridge forming elementopposite the point of needle penetration in the fabric for engaging theneedle thread loop and holding the same for re-entrance by the needle,said looper being supported for oscillatory movements about a verticalaxis and including a curved beak movable in a horizontal plane, andthread severing means operative above the foot and between the looperand the needle when the latter is at the beginning of its stroke.

15. In a single thread blind stitch sewing machine, the combination witha stationary presser foot having an opening, a threaded needle locatedabove the foot for reciprocations transversely across the presser footopening, a ridge forming element for projecting a ridge of fabricupwardly through the opening into needle penetrating position, means forfeeding the fabric to the needle, a non-threaded looper located abovethe foot and operating entirely on the side of the ridge forming elementopposite the point of needle penetration in the fabric for engaging theneedle thread loop and holding the same for reentrance by the needle, astationary knife located above the foot and between the looper and theneedle when the latter is at the beginning of its stroke, a manuallyoperable carrier arm for raising the leg of the needle loop extendingaround the looper into cooperative cutting relation with said knife,means for yieldably retaining the carrier arm against upward movement,and manually operable means for raising the carrier arm against thetension of said yieldable means. s

16. In a single thread blind stitch sewing machine, the combination witha stationary presser foot having an opening, a threaded needle locatedabove. the foot for reciprocations transversely across the presser footopening, a ridge forming element for projecting a ridge of fabricupwardly through the opening into needle penetrating position, means forfeeding the fabric to the needle, a non-threaded looper located abovethe foot and operating entirely on the side of the ridge formingelementopposite the point of needle penetration in the fabric for engaging theneedle thread loopand holding the same for re-entrance by the needle, astationary knife located above the foot and between the looper and theneedle when thellatter is at the beginning of its stroke, a manuallyoperable carrier arm for raising the leg of the needle loop extendingaround the looper into, cooperative cutting relation with said knife,the free end of the arm being slotted to formv resultant threadsupporting arms movable to opposite sides of the knife, means foryieldably retaining the carrier arm against upward movement, andmanually operable means for raising the carrier arm against the tensionof said yieldable means.

17. In a single thread blind stitch sewing machine, the combination witha stationary presser foot having an opening, a threaded needle locatedabove the foot for reciprocations transversely across the presser footopening, a ridge forming element for projecting a ridge of fabricupwardly through the opening into needle penetrating position, means forfeeding the fabric to the needle, a non-threaded looper located abovethe foot and operating entirely on the side of the ridge forming elementopposite the point of needle penetration in the fabric for engaging theneedle thread loop and holding the same for re entrance by the needle, athread clamp located between the looper and the needle when the latteris at the beginning of its forward stroke, a thread cutting knife, andmeans located between the thread clamp and the looper for firstpositioning the leg of the needle loop extending around the looper intothe thread clamp and for subsequently moving said thread into severingrelation with said knife.

18. In a single thread blind stitch sewing machine, the combination witha stationary presser foot having an opening, a threaded needle locatedabove the foot for reciprocations transversely across the presser footopening, a ridge forming element for projecting a ridge of fabricupwardly through the opening into needle penetrating position, means forfeeding the fabric to the needle, a non-threaded looper located abovethe foot and operating entirely on the side of the ridge forming elementopposite the point of needle penetration in the fabric for engaging theneedle thread loop and holding the same for reentrance by the needle, athread clamp located between the looper and the needle when the latteris at the beginning of its forward stroke, a thread cutting knife, andmeans located between the thread clamp and the looper for firstpositioning the leg of the needle loop extending around the looper intothe thread clamp and for subsequently moving said thread into severingrelation with said knife, said clamp comprising vertically disposedclamping arms forming a resultant thread receiving throat at their lowerend and located directly above said leg of the needle loop.

19. In a single thread blind stitch sewing machine, the combination witha stationary presser foot having an opening, a threaded needle locatedabove the foot for reciprocations transversely across the presser footopening, a ridge forming element for projecting a ridge of fabricupwardly through'the opening into needle penetrating position, means forfeeding the fabric to the needle, a non-threaded looper located abovethe foot and operating entirely'on the side of the ridge forming elementopposite the point of needle penetration in the fabric for engaging theneedle thread loop and holding the same for reentrance by the needle, athread clamp located between 'the looper and the'needle when the latteris at the beginning of its forward stroke, a thread cutting knife, andmeans located between the thread clamp and the looper for firstpositioning the leg of the needle loop extending around the looper intothe thread clamp and for subsequently moving said thread into severingrelation with said knife, said positioning means 7 comprising a carrierarm fulcrumed on the presser a non-threaded looper located above thefoot and operating entirely on the side of the ridge forming elementopposite the point of needle penetration in the fabric for engaging theneedle thread loop and holding the same for re-entrance by the needle, athread clamp located between the looper and the needle when the latteris at the beginning of its forward stroke, a thread cutting knife, andmeans located between the thread clamp and the looper for firstpositioning the leg of the needle loop extending around the looper intothe thread clamp and for subsequently moving said thread into severingrelation with said knife, said positioning means comprising a carrierarm fulcrumed on the presser foot in rear of the needle path and havingits forward end normally disposed under said leg of the needle loop,means for yieldably retaining the carrier arm against upward movement,and manually operable means for raising the carrier arm against thetension of said yieldable means.

21. In a single thread blind stitch sewing machine, the combination witha stationary presser foot having an opening, a threaded needle locatedabove the foot for reciprocations transversely across the presser footopening, a ridge forming element for projecting a ridge of fabricupwardly through the opening into needle penetrating position, means forfeeding the fabric to the needle, a non-threaded looper located abovethefoot and operating entirely on the side of the ridge forming elementopposite the point of needle penetration in the fabric for engaging theneedle thread loop and holding the same for re-entrance by the needle, athread clamp located between the looper and the needle when the latteris at the beginning of its forward stroke, a stationary knife locatedabove the foot, and means located between the thread clamp and thelooper for first positioning the leg of the needle loop extending aroundthe looper into the thread clamp and for subsequently cooperating withthe knife in severing said thread, said last named means comprising acarrier arm fulcrumed on the presser foot in rear of the needle path andhaving its forward end normally disposed under said leg of the needleloop, the free end of the arm being slotted to form resultant threadsupporting arms movable to opposite sides of the knife, means foryieldably retaining the carrier arm against upward movement, andmanually operable means for raising the carrier arm against the tensionof said yieldable means.

22. In a single thread blind stitch sewing machine, the combination witha stationary presser foot having an opening, a threaded needle locatedabove the foot for reciprocations transversely across the presser footopening, a ridge forming element for projecting a ridge of fabricupwardly through the opening into needle penetrating position, means forfeeding the fabric to the needle, a non-threaded looper located abovethe foot and operating entirely on the side of the ridge forming elementopposite the point of needle penetration in the fabric for engaging theneedle thread loop and holding the same for re-entrance by the needle, athread clamp located between the looper and the needle when the latteris at the beginning of its forward stroke comprisingv verticallydisposed clamping arms forming a resultant thread receiving throat attheir lower end and located directly above said leg of the needle loop,a thread cutting knife, and means located between the thread clamp andthe looper for first positioning the leg of the needle loop extending23. In a blind stitch sewing machine, the combination with a frame, of astationary presser foot mounted on said frame and having an openingtherein, a stitch forming mechanism mounted on the frame above the footand including a threaded needle mounted for reciprocations across theopening in said foot, a depressible work support mounted on the framebelow the foot, a ridge forming element mounted on the work support forprojecting a ridge of fabric upwardly through the opening into needlepenerating position, normally inoperative means for severing the needlethread above the foot, and

means for rendering the severing means effective upon depression of thework support.

24. In a blind stitch sewing machine, the combination with a frame, of astationary presser foot mounted on said frame and having an openingtherein, a stitch forming mechanism mounted on the frame above the footand including a threaded needle mounted for reciprocations across theopening in said foot, and a cooperating loop taker,

' a depressible work support mounted on the frame below the foot, aridge forming element mounted on the work support for projecting a ridgeof fabric upwardly through the opening into needle penetrating position,a thread clamp located between the loop taker and the needle when thelatter is at the beginning of its stroke, a thread cutting knife,normally inoperative means for first positioning the leg of the needlethread extending from the needle into the thread clamp and forsubsequently moving said thread into severing relation with said knifeat a point between the clamp and the fabric being stitched, and meansfor rendering said positioning and severing means effective upondepression of the work support.

25. In a single thread blind stitch sewing machine, the combination witha frame, of a station'- ary press-er foot mounted on said frame andhaving an opening therein, a stitch forming mechanism mounted on theframe above the foot and including a threaded needle mounted forreciprocations across the opening in said foot and a cooperatingnch-threaded looper, a depressible work support mounted on the framebelow the foot, a ridge forming element mounted on the work support forprojecting a ridge of fabric upwardly through the opening into needlepenetrating position, normally inoperative means for severing the needlethread between the looper and the needle when the latter is at thebeginning of its stroke, and means for rendering the severing meansoperative upon depression of the work support.

26. In a single thread blind stitch sewing machine, the combination witha frame, of a stationary presser foot mounted on said frame and havingan opening therein, a stitch forming mechanism mounted on the frameabove the foot and including a thread-ed needle mounted forreciprocations across the opening in said foot and a cooperatingnon-threaded looper, a depressible work support mounted on the framebelow the foot, a ridge forming element mounted on the work support forprojecting a ridge of fabric upwardly through the opening into needlepenetrating position, a thread clamp located between the looper and theneedle when the. latter is at the beginning of its stroke, a threadcutting knife, normally inoperative means for Ifirst positioning the legof the needle thread extending from the needle into the thread clamp andfor subsequently moving said thread into severing relation with saidknife at a pointbetween the clamp and the fabric being stitched, andmeans for rendering said positioning and severing means effective upondepression of the work support.

27. .In a single thread blind. stitch sewing'machine, the combinationwith a frame, of a stationary presser foot mounted on said frame;

and having an opening therein, a stitch forming mechanism mounted on theframe above the foot and including a threaded needle mounted for.reciprocationsacross the opening in said foot and cooperatingnon-threaded looper, a depressible work support mounted on the framebelow the foot, a ridge forming element mounted on the work support forprojecting a ridge of fabric. upwardly through the opening into needlepenetrating position, a thread clamp located between the looper and theneedle when'the latter is at the beginning of its forward stroke,normally inop-' erative .thread severing means located between thelooper and the clamp and including a sta tionary knife and a verticallymovable carrier arm, and means operableupon depression of the worksupport for elevating the carrier arm to first position the leg of theneedle loop extending around the looper into the thread clamp and forsubsequently positioning said thread leg into cooperating cuttingrelation with said knife.

28; In a blind stitch sewing machine, the combination'with a frame.including a standard and a laterally extending arm, of a horizontalpresser foot fixed to the free end of said arm and having. an opening, astitch formingmechanism mounted. on said arm above the foot andincluding a threaded needle mounted for reciprocations across theopening in the foot, a depressible work support mounted on the frame andlocated below said foot, a ridge forming element mounted on the worksupport for projecting a ridge of fabric upwardly through the openinginto needle penetrating position, normally inoperative means forsevering the needle thread above the foot, and means for rendering thesevering means operative upon depression of the work support.

29. In a blind stitch sewing machine, the com-.

bination with a frame including a standard and a laterally extendingarm, of a horizontal presser foot fixed to the free end of said arm andhaving an opening, a stitch forming mechanism mounted on said arm abovethe foot and including a threaded needle mounted for reciprocationsacross the opening in the foot, a pivoted work support mounted on theframe and located below said foot, a ridge forming element mounted onthe work support for projecting a ridge of fabric upwardly through theopening into needle penetrating position, a stationary knife mounted onthe arm above the foot, a normally inoperative carrier arm supported onthe arm below the knife, and connections between the carrier arm and thework support for operating the former upon depression of the latter toelevate the needle thread into cutting relation with said knife.

30. In a blind stitch sewing machine, the combination with a frameincluding a standard and a laterally extending arm, of a horizontalpresser foot fixed to the free end of said arm and having an opening, astitch forming mechanism mounted on said arm above the foot andincluding a 8. threaded needle mounted for reciprocations across theopening in the foot, a pivoted work support mounted on the frame andlocated below forming element mounted on ecting a ridge of fabric,

said foot, a ridge the work support for proj upwardly through theopening into needle penetrating position, a stationary knife mounted onthe arm above the foot, a horizontal rock shaft 31. In a blind stitchsewing machine, the combination with a frame including a standard and alaterally extending arm, of a horizontal presser foot fixed to the freeend of said arm and having an opening, a stitch forming mechanismmounted on said arm above the foot and including a threaded needle'mounted for reoiprocations across the opening in the foot, a pivotedwork support mounted on the frame and located below said foot, a ridgeforming element mounted on the work support for projecting a ridge offabric upwardly through the opening into needle penetrating position, astationary knife mounted on the arm above the foot, a horizontal rockshaft journaled on the presser foot, a thread carrier arm fixed to therock shaft for elevating the needle thread into cutting relation withthe knife,

and means for operating the rock shaft upon depression of the worksupport including a lever fulcrumed on the frame arm and an arm fixed tothe work support for operating said lever.

32. In a blind stitch sewing machine, the combination with a frameincluding a standard and a laterally extending arm, of a horizontalpresser foot fixed to the free end of said arm and having an opening, astitch forming mechanism mounted on said arm above the foot andincluding a threaded needle'mounted for reciprocations across theopening in the foot, a pivoted work support mounted on the frame andlocated below said foot, a ridge forming element mounted on the worksupport for projecting a ridge'of fabric upwardly through the openinginto needle penetrating position, a stationary knife mounted on the armabove the foot, a horizontal rock shaft journaled on the presser foot, athread carrier arm fixed to the rock shaft for elevating the needlethread into cutting relation with the knife, means for yieldablyretaining the carrier arm against upward movement, and means foroperating the rock shaft against the tension of said yieldable meansupon depression. of the work support.

33. In a blind stitch sewing machine, the combination with aframeincluding a standard and a laterally extending arm, of a horizontalpresser foot fixed to the free end of said arm and having an opening, astitch forming mechanism mounted on said arm above the foot andincluding a threaded needle mounted for reciprocations across theopening in the foot, a depressible work support mounted on the frame andlocated below said foot, a ridge forming element mounted on the worksupport for projecting a ridge of fabric upwardly through the openinginto needle penetrating position, a stationary knife mounted on the armabove the foot, a normally inoperative carrier arm supported on the armbelow the knife, a thread clamp supported on the frame arm intermediatethe knife and the carrier arm, and connections between the carrier armand the work support for operating the former upon depression of thelatter to elevate the needle thread first into the clamp andthen intocutting relation with said knife.

34. In a single thread blind stitch sewing machine, the combination witha frame including a base, a standard, and an arm extending laterallyfrom the upper end of the standard and terminating in a forwardlyextending arm, of a horizontal presser foot fixed to the free end of theforwardly extending arm and having an opening therein, a work supportpivoted on the base to swing about a horizontal axis in parallelism withthe lateral arm and having a forward depressible portion located under.the foot, said work support having a portion extending rearwardly ofthe pivot, a stitch forming mechanism. mounted on the forwardlyextending arm and including a threaded needle mounted for reciprocationsacross the presser foot opening and a cooperating nch-threaded looper, astationary knife mounted on said forwardly extending arm above the foot,a rock shaft journaled on the foot, a thread carrier arm fixed to therock shaft for elevating the leg of the needle loop extending betweenthe looper and the needle into cutting relation with said knife, andmeans for rocking said shaft upon depression of the work support in-.

cluding a lever fulcrumed on the forwardly extending arm and an armfixed to the rear portion of the work support for operating said lever.

LOUIS G. BOWMAN.

